191212-50-7Relevant articles and documents
Synthesis of (S)- and (R)-sporochnol by using the allylic substitution of the secondary allylic picolinate
Kobayashi, Yuichi,Sugihara, Yusuke,Tojo, Toshifumi,Ozaki, Takuri
, p. 47 - 54 (2016)
The allylic substitution of secondary allylic picolinates and copper reagents for the construction of a quaternary carbon was applied to synthesis of sporochnol. The enantiomerically enriched allylic picolinate (R)-5 was synthesized through the asymmetric hydrogen transfer of acetylene ketone 11 and the Pd-catalyzed methylation of the iodoallylic alcohol 16a. The key allylic substitution of the allylic picolinate (R)-5 with 4-MeOC6H4MgBr/Cu(acac)2 (2:1) proceeded with 95% chirality transfer with 98% regioselectivity to afford anti SN2' product 6 in 89% yield, which was converted to the methyl ether of unnatural (R)-sporochnol. Similarly, the methyl ether of (S)-sporochnol (the natural form) was synthesized.
Quaternary carbon stereogenic centers through copper-catalyzed enantioselective allylic substitutions with readily accessible aryl- or heteroaryllithium reagents and aluminum chlorides
Gao, Fang,Lee, Yunmi,Mandai, Kyoko,Hoveyda, Amir H.
supporting information; experimental part, p. 8370 - 8374 (2010/12/25)
The case of the notorious aryls is solved: The first efficient catalytic and enantioselective method for allylic substitutions that furnish quaternary carbon stereogenic centers by additions of aryl- or heteroarylmetals is reported (see scheme). Highly site- and enantioselective processes begin with readily available organolithium reagents.
The absolute configuration of (+)-sporochnol A, the fish deterrent from the Caribbean marine alga Sporochnus bolleanus
Takahashi, Michiyasu,Shioura, Yoko,Murakami, Taku,Ogasawara, Kunio
, p. 1235 - 1242 (2007/10/03)
The absolute configuration of (+)-sporochnol A, the fish deterrent from the Caribbean marine alga Sporochnus bolleanus, has been established as S based on the stereocontrolled synthesis of its (R)-(-)-enantiomer from (S)-epichlorohydrin.